Obtaining distributed unit's configuration information by a central unit of a base station

Abstract

A method is presented in which a central unit of a distributed base station apparatus in a cellular communication system sends to a distributed unit of the distributed base station apparatus a first message comprising an information element for requesting the distributed unit of the distributed base station to provide a current distributed unit configuration. The central unit receives, from the distributed unit of the distributed base station apparatus, configuration information for the current distributed unit configuration in a second message sent in response to the first message.

The invention claimed is: 
     
       1. A method performed by a Central Unit (CU) of a distributed base station, the method comprising:
 sending, to a source Distributed Unit (DU) of the distributed base station, a user equipment (UE) CONTEXT MODIFICATION REQUEST message including a Configuration Query information element (IE) for requesting configuration information of the source DU, where the UE is determined to move from the source DU to a target DU of the distributed base station; 
 receiving, from the source DU, a UE CONTEXT MODIFICATION RESPONSE message including configuration information indicating a cell group configuration of the source DU based on the UE CONTEXT MODIFICATION REQUEST message including the Configuration Query IE; and 
 sending the configuration information indicating the cell group configuration of the source DU to the target DU or another base station. 
 
     
     
       2. The method according to  claim 1 , further comprising receiving a request from the another base station,
 wherein the sending the UE MODIFICATION REQUEST is performed based on the request. 
 
     
     
       3. The method according to  claim 1 , wherein the sending the configuration information indicating the cell group configuration of the source DU is performed by sending, to the target DU, the configuration information indicating the cell group configuration of the source DU,
 wherein the method further comprises receiving, from the target DU, configuration information indicating a cell group configuration of the target DU, and 
 wherein the configuration information indicating the cell group configuration of the target DU includes delta configuration information representing a change from the cell group configuration of the target DU to the cell group configuration of the source DU. 
 
     
     
       4. The method according to  claim 3 , wherein the sending the configuration information indicating the cell group configuration of the source DU is performed by sending, to the target DU, the configuration information indicating the cell group configuration of the source DU, in a UE context setup message, and
 wherein the receiving the configuration information indicating the cell group configuration of the target DU is performed by receiving, from the target DU, the configuration information indicating the cell group configuration of the source DU, in a UE context setup response message. 
 
     
     
       5. A Central Unit (CU) of a distributed base station, the CU comprising:
 a transceiver; and 
 a controller configured to control the transceiver to:
 send, to a source Distributed Unit (DU) of the distributed base station, a user equipment (UE) CONTEXT MODIFICATION REQUEST message including a Configuration Query information element (IE) for requesting configuration information of the source DU, where the UE is determined to move from the source DU to a target DU of the distributed base station; 
 receive, from the source DU, a UE CONTEXT MODIFICATION RESPONSE message including configuration information indicating a cell group configuration of the source DU based on the UE CONTEXT MODIFICATION REQUEST message including the Configuration Query IE, and 
 send the configuration information indicating the cell group configuration of the source DU to the target DU or another base station. 
 
 
     
     
       6. A non-transitory computer-readable storage medium having instructions stored thereon, which when executed by at least one processor of a Central Unit (CU) of a distributed base station, cause the CU to:
 send, to a source Distributed Unit (DU) of the distributed base station, a user equipment (UE) CONTEXT MODIFICATION REQUEST message including a Configuration Query information element (IE) for requesting configuration information of the source DU, where the UE is determined to move from the source DU to a target DU of the distributed base station; 
 receive, from the source DU, a UE CONTEXT MODIFICATION RESPONSE message including configuration information indicating a cell group configuration of the source DU based on the UE CONTEXT MODIFICATION REQUEST message including the Configuration Query IE, and 
 send the configuration information indicating the cell group configuration of the source DU to the target DU or another base station.